Light-permeable sound-absorbing panel



Y Sept. 2,'1958 R. A. BENJAMIN LIGHT-.'PERMEABLE SOUND-ABSORBING PANELFiled April 27, 1954 S f L V United States Patent O LIGHT-PERMEABLESOUND-ABSRBING PANEL Reuben Allen Benjamin, Glencoe, lll., assignor toBen- ]amln Electric Manufacturing Company, Glencoe, Ill., a corporationof Illinois Application April 27, 1954, Serial No. 425,855

7 Claims. (Cl. 181-33) This invention relates to the acoustical andoptical treatment of rooms, more particularly to the provision oflight-permeable and sound-absorbing panels for utilization as individualmembers or in connection with lighting fixtures, and it is an object ofthe 'invention to provide improved apparatus of this character.

It is a further object of the invention to provide a panel of thecharacter described which is simple in construction, ecient inoperation, and pleasing in appearance. l

In many rooms, whether oces, studios or factories, it is desirable tohave' sound-deadening means and, conveniently, these may be provided inconnection with lighting fixtures, particularly those of the fluorescentlamp type, in order not lonly to absorb sound from the light fixtureitself, but from the surroundings.

Sound-deadening panels or baffles of the prior art have been eitheropaque to `light `or the exterior surface of the panel has been solid sothat sound waves impinging thereon were reflected to a substantialextent. Accordingly, it is a further object of the invention to providean improved light-permeable, sound-absorbing panel wherein the exteriorsurface is sound-transparent over the sound frequency range, but theinterior of the panel is highly effectively sound-absorbing over thesame range so that sound after having entered the panel is absorbed ordeadened and never emerges. In carrying out the invention in one form alight-permeable, sound-absorbing panel is provided comprising a pair ofspaced apart perforated layers of light-permeable material and a layerof light-permeable, sound-absorbing material disposed in the spacebetween the perforated layers.

For a more complete understanding of the invention reference should behad to the accompanying drawings, in which Figure l is a view partiallyin section showing a panel according to the invention suspended from theceiling of a room in connection with a uorescent lighting tixture;

Fig. 2 is a fragmentary view taken in the direction of arrows 2--2 ofFig. l;

Fig. 3 is a sectional view on a larger scale taken substantially alongthe line 3 3 of Fig. 2;

Fig. 4 is a fragmentary view similar to Fig. 2 of a modified form of theinvention; and

Fig. 5 is a sectional view taken substantially :along the line 5-5 ofFig. 4.

Referring to the drawings, the invention comprises a light-permeable,sound-absorbing panel shown suspended from a ceiling 11 beneath a pairof fluorescent lamps 12 Iand 13, the suspension being by means of rods14 or other suitable means.

The panel 10 comprises a pair of perforated members 15 and 16 which arespaced apart and between which there is a layer of sound :absorbingmaterial 17. As shown in Figs. 1 and 2, the layers 15 and 16 may be incontact with the surfaces of the layer of sound-absorb- Patented Sept.l2, 1958 ICC ing material 17, but it will be understood that the layers15 and 16 may be spaced a short distance away from the sound-absorbingmaterial. The layers 15 and 16 may be held apart in any suitable mannerso as not to crush the sound-absorbing material, such for example as byspacers 18.

The layers 15 and 16 may be made, for example, of a clear or translucentplastic material provided with perforations 19, which perforations may,for example, be of the order of 1A inch to W16 inch in diameter andspaced on centers 3A inch to 11A inch apart. The size, number, andspacing of the perforations,'as well as the thickness of the layers 15and 16, may be chosen to satisfy particular conditions so long as thedimensions are such that the layers 15 and 16 are substantiallytransparent to sound over the sound frequency range.

The material 17 may be any translucent or transparent wool, for examplemade `o'f spun glass or rock fibers which are highly sound absorbingover the sound frequency range. Thus, when sound impinges upon thelayers 15 and 16 it passes therethrough by virtue of the perforationsand then is absorbed within the wool layer 17, the thickness thereofbeing chosen to satisfy the particular conditions. One to two inches inthickness has been found satisfactory.

The panel as a whole should be light-permeable in order that use may bemade of it in connection with lighting fixtures and it may be as nearlytransparent as the materials desired to be used will permit. It mayalso, of course, be translucent whereby to produce a desirable diffusedeffect. Various decorative effects may be produced by using coloredmaterials, for example, for the layers 15 and 16.

To obtain a slight spacing of a substantial portion of the exteriorlayers from the sound-absorbing material, these layers may be corrugatedas shown by layers 2l and 22 in Figs. 4 and 5. The materials of layers21 and 22 may be the same as those described in the preceding gures andthe perforations 23 may be dimensioned and disposed as alreadydescribed, but as shown are disposed only in the tops or outermost partsof the corrugations. Perforations may also be provided in the bottoms ofthe corrugations, if desired. A layer of highly efficientsound-absorbing, light-permeable material 24 is disposed between thecorrugated layers 21 and 22 so that contact is had for support purposesonly with the bottoms or innermost parts of the corrugations. In a panelconstructed in this fashion, the sound enters the perforations 23 andspreads out within the triangular spiace between the perforations andthe surface of the wool-absorbing material 24 so that the sound impingesinitially upon the sound material over a larger area thereof. A greaterportion of the wool-absorbing materialcomes into operation and a greatersound-absorbing or deadening effect is obtained.

While particular embodiments of the invention have been shown, it willbe understood, of course, that the invention is not limited theretosince many modications may be made, and it is, therefore, contemplatedby the appended claims to cover any such modifications as fall withinthe true spirit and scope of the invention.

The invention having thus been described, what is claimed and desired tobe secured by Letters Patent is:

l. A light-permeable, sound-absorbing panel comprisign a pair ofspaced-apart, perforated layers of lightpermeable, material, and a layerof light-permeable, sound-absorbing material disposed in the spacebetween said perforated layers.

2. A light-permeable, sound-absorbing panel comprising a pair ofspaced-apart, perforated layers of lightpermeable material, and a layerof fibrous, lightpermeable material disposed in the space between saidperforated layers.

3. A light-permeable, sound-absorbing panel comprising a pair ofspaced-apart, perforated layers of lightpermeable material, spacers forholding said perforated layers in said spaced-apart relationship, and alayer of fibrous, light-permeable material disposed in the space betweensaid perforated layers.

4. A light-permeable, sound-absorbing panel comprising a pair ofspaced-apart, perforated layers of lightpermeable material, spacers forholding said perforated layers in said spaced-apart relationship, and alayer of fibrous, light-permeable material disposed in the space betweensaid perforated layers but spaced therefrom.

5. A light-permeable, sound-absorbing panel comprising a pair ofcorrugated, spaced-apart, perforated layers of light-permeable material,and a layer of fibrous, lightpermeble material disposed in the spacebetween said perforated layers.

6. A light-permeable, sound-absorbing panel comprising a pair ofcorrugated, spaced-apart, perforated layers of light-permeable material,and a layer of fibrous, lightpermeable material disposed in the spacebetween said perforated layers but being in contact only with theinnermost parts of the Acorrugations thereof.

7. A light-permeable, sound-absorbing panel comprising a pair ofcorrugated, spaced-apart layers of lightpermeable material, each of saidlayers being perforated along the outermost parts of the corrugationsthereof, and a layer of fibrous, light-permeable material disposed inthe space between said perforated layers but being in contact only withthe innermost parts of the corrugations three'of.

References Cited in the file of this patent UNITED STATES PATENTS2,011,252 Modigliani Aug. 13, 1935 2,160,638 Bedell et al, May 30, 19392,161,708 Heerwagen June 6, 1939 2,218,992 Monroe Oct. 22, 19402,590,204 Phillips Mar. 25, 1952 2,710,335 Wong June 7, 1955 2,715,449Lemmerman et alv Aug. 16, 1955 2,759,093 Ferar et al. Aug. 14, 1956

